The object is to elucidate the mechanism of enzyme catalyzed reactions and related phenomena such as ligand binding by hemoglobin, and protein-protein interactions, by making observations on the chemical and physical properties of appropriate systems, often of a kinetic character. The observations will be compared with suitable model systems and correlated with structural and chemical information available to build up a descriptive scheme best approximating the experiment. BIBLIOGRAPHIC REFERENCES: Seybert, D.W., Moffat, K., and Gibson, Q.H., Ligand Binding Properties of Horse Hemoglobins Containing Deutero-and Mesoheme. J. Biol. Chem., 251, 45 (1976). Saffran, W A., and Gibson, Q.H., Kinetics of the Bohr Effect of Menhaden Hemoglobin, Brevoortia Tyrannus, BBRC 69, 383 (1976).